Recent models of the development of planning suggest that planning is often context-dependent, although there is not agreement as to whether plans become more or less contextualized with development. Even where there is agreement, there is ambiguity as to what context means. Although context effects have been examined in both the problem-solving and motivational literatures, the results do not provide a more general framework of contextual dimensions, especially for real-life tasks. In addition, it is often assumed that individuals will respond to certain contextual cues in the same way. The proposed model combines the planning, problem-solving, and motivational literatures and suggests that context and individual characteristics (including age) must be considered simultaneously to predict whether and how planning occurs at a particular point in time. The goal of the proposed research is to examine how planning for a particular activity varies as a function of how the activity is perceived and defined. Dimensions of the context in which an activity is performed (e.g., time, place, evaluation, etc.) can impact an individual's perception; and individuals may be differentially sensitive to particular contextual dimensions as a function of age, experience, abilities, motivation, etc. More specifically, the goals of the five proposed studies are to 1) identify the contextual dimensions people are able to perceive across the life span in everyday activities, 2) determine whether particular dimensions are more salient in certain domains (i.e., health, work, school, family, friends, leisure) and/or for certain individuals (i.e., individuals of specific ages or experience levels) and whether these dimensions affect the incidence of planning in these domains, and 3) whether differential salience results in different activity definitions. To examine how different definitions of the same activity affect planning, the studies will examine the effects of differential activity definitions on 1) individuals' goals, 2) the planning process, and 3) the product or plan, itself. In addition, the studies will examine the subsequent evaluation of these plans in terms of anticipated effectiveness and relevance to perceived goals.